Insulating Lost Formwork

ABSTRACT

Disposable framework ( 1 ) for insulated masonry in reinforced concrete, is provided with two polystyrene panels ( 2 ) which face each other and which are limited towards the outside by respective lateral surfaces ( 2   e ), and with at least two formwork spacers ( 10 ) which are assembled to the polystyrene panels ( 2 ), and presenting respective pairs of terminal end plates ( 19 ), which extend in such a way as to abut the ralative lateral surfaces ( 2   e ) and which partially occupy a height of the lateral surfaces ( 82   e ).

The present invention refers to a disposable formwork for insulated masonry in reinforced concrete.

The American U.S. Pat. No. 5,390,459 refers to a disposable formwork for masonry in reinforced concrete which comprises two polystyrene panels which face each other and which are limited towards the outside by respective lateral surfaces, and at least two formwork spacers which are co-moulded together with the polystyrene panels, and which present respective pairs of terminal end plates, which extend in such a way as to abut the relative lateral surfaces, occupying all the height of the lateral surfaces themselves.

In the kind of formworks which have just been described, the formwork spacers are generally made of plastic material, and the formworks are assembled to one another in such a way as to create walls which are provided with a number of vertical plastic bands, which are defined by the union between the terminal end plates in order to provide greater structural stability to the walls themselves, and which define discontinuities on the external surfaces of the walls which are otherwise constituted by the polystyrene of which the panels are made.

In practice, it has been discovered that such discontinuities can lead to some disadvantages with reference to the sealing capacity of the successive layers of protective and waterproofing plaster in that the composition of the latter is aimed at permitting the best possible adhesion between the polystyrene of the panels and the plastic material of the formwork spacers.

The aim of the present invention is to produce a disposable formwork for insulated masonry in reinforced concrete which will be free of the above-described disadvantages.

According to the present invention, a disposable formwork for insulated masonry in reinforced concrete will be produced, the formwork comprising two polystyrene panels which face each other and which are limited towards the outside by respective lateral surfaces, and at least two formwork spacers which are assembled together with the polystyrene panels, and presenting respective pairs of terminal end plates: the formwork being characterised by the fact that the terminal end plates extend in such a way as to abut the relative lateral surfaces and partially occupy a height of the lateral surfaces themselves.

An additional aim of the present invention is also to produce a disposable formwork for insulated masonry in reinforced concrete, which will present a low volume in the transport phase, and which also be easy and quick to install.

In fact, in the case of the disposable formwork which is referred to in the above-mentioned American Pat. No. 5,390,459, the formwork spacers are produced in a single block of plastic material, and they cannot make the relative formworks assume a collapsed configuration like the one which is described in, for example, the further American Pat. No. 3,985,328, in which the formwork spacers are each provided with two hinges in order to permit a reciprocal approach of the two polystyrene panels during the transport phase.

The disposable formwork which is described in the further American patent presents, however, the disadvantage of being difficult to conform in a stable placement configuration due to the fact that the hinges of the formwork spacers render any configuration whatsoever of the formwork instable, apart from the collapsed configuration.

Thus, according to the present invention the disposable formwork for insulated masonry in reinforced concrete comprises, in addition, two hinges which are associated with each formwork spacer in order to permit the collapse of the disposable formwork itself in a transport configuration, and movement blocking devices of the hinges themselves in order to block the two polystyrene panels in a stable placement configuration.

The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting form of embodiment of the present invention, and in which:

FIG. 1 is an elevated lateral view of a first preferred form of embodiment of a disposable formwork for insulated masonry in reinforced concrete produced according to the present invention;

FIG. 2 is a plan view of the disposable formwork which is shown in FIG. 1 in an operating placement configuration;

FIG. 3 is a plan view of the disposable formwork which is shown in FIG. 1 in an operating transport configuration;

FIG. 4 is a lateral elevation view of the disposable formwork which is shown in FIG. 1;

FIGS. 5 and 6 illustrate, in perspective views, a detail of the disposable formwork which is shown in FIG. 1 in respective operating configurations: and

FIGS. 7, 8 and 9 are frontal elevation schematic views, with some parts removed for reasons of clarity, of the same number—three—of preferred forms of embodiment of the disposable formwork which is shown in FIG. 1;

FIG. 10 illustrates a perspective view from above of a detail of the disposable formwork which is shown in FIG. 1; and

FIG. 11 illustrates, on an enlarged scale and with some parts removed for reasons of clarity, a detail which is shown in FIG. 10.

With reference to FIG. 1, the number 1 refers to a disposable formwork for insulated masonry in reinforced concrete in its entirety.

The formwork 1 presents a major longitudinal axis A, and comprises two polystyrene panels 2 which face each other and are parallel to each other and to the axis A itself. The panels 2 are delimited towards the outside by respective external lateral surfaces 2 e, and are both limited towards the inside by respective lateral surfaces 2 i which are provided with a number of vertical recesses R. In particular, the recesses R extend for the whole of a height H of the panels 2, and present a shape in the form of a swallow's tail in a transverse section.

Each panel 2, which is preferably of a parallelepiped shape, is, in addition, delimited by an upper surface 2 s and a lower surface 2 f, which are parallel to each other and transverse to the relative surfaces 2 i and 2 e, and, with the aim of assembling a panel 2 itself with other panels 2, present a number of quadrangular bulges 3 and notches 4 which are arranged in rows parallel to the axis A in such a way that, as is illustrated in FIG. 2, the bulges 3 and the notches 4 in one row are staggered in relation to the bulges 3 and the notches 4 in the adjacent row or rows.

In addition, the formwork 1 comprises two or more formwork spacers 10 which are preferably but not necessarily assembled by means of co-moulding to the panels 2, and each comprise, as is illustrated in FIGS. 4, 5 and 6, a respective intermediate crosspiece 11, and two anchoring portions 12 which are arranged at opposite ends of the crosspiece 11.

In addition, each spacer 10 comprises two connecting hinges 13, which connect each portion 12 to the crosspiece 11, and which are suitable for permitting the rotation of each portion 12 in relation to the crosspiece 11 itself around a respective axis B transverse to the axis A from a closed configuration (see FIG. 8), in which the two portions 12 are arranged transverse to the crosspiece 11, to a placement configuration (see FIG. 5), in which the two portions 12 are arranged in alignment with the crosspiece 11.

The crosspiece 11 comprises two bridge elements 11 a and 11 b, which present an equal flattened shape, and which are arranged on the same plane and are parallel to each other, and are at a determined distance from each other in such a way as to define a window 14 in relation to each other, which is also delimited by the portions 12.

The elements 11 a and 11 b each comprise, and on each free longitudinal side, three flattened support saddles 15, which are arranged next to each other, and which are suitable for permitting the safe positioning of the reinforcement rods (which are not illustrated). In addition, the elements 11 a and 11 b each comprise, and in correspondence to the respective opposite longitudinal ends, a grooved body 16, which presents an inner passing hole 16 a, and which is laterally delimited towards the outside by a grooved surface 16 s.

In the form of embodiment which is herein described and illustrated each portion 12 is partially embedded inside a relative panel 2, and comprises two plates 18 and 19 which are arranged parallel to and facing each other and transverse to the crosspiece 11, and a number of connecting fins 20, which are interposed between the two plates 18 and 19 themselves, and are arranged through the relative panel 2.

In particular, the plate 18 is arranged in such a way as to abut the surface 2 i of the panel 2, and is provided, on the opposite side to the fins 20, with a rigid rib 21 which is transverse to the plate 18 and is integral, for part of its own length, with the plate 18 itself, while it departs from the plate 18 in correspondence with its own opposite free end in order to define two elastic pins 22.

The elastic pins 22 are inserted inside the holes 16 a of the relative bodies 16, and each comprise two forked teeth 23 which face each other in order to form an open notch 24, and, for each tooth 23, a blocking undercut 25 which is arranged outside the body 16 in order to axially block the body 16 and the pin 22 themselves.

According to a form of embodiment which is not illustrated, but which is easily understandable from the foregoing description, each plate 18 may be provided, in the place of the relative plate 19 and the relative connecting fin 20, with a grooved rib in the shape of a swallow's tail in such a way that it can be firmly inserted inside a relative recess R. Such a solution would also permit the use of formwork spacers 10 on panels 2 which have already been constructed; this would also be permitted in the case of inserting anchoring portions 12 inside slots—which are not illustrated—obtained through the panels 2.

In the form of embodiment which is currently being described, however, the plate 19 is arranged outside the panel 2 in order to permit the easy identification of the position of the relative formwork spacer 20 along the panel 2 itself, and is arranged in such a way as to completely abut the surface 2 e of the panel 2 itself.

The plate 19 presents a length L of dimensions which are less than the height H of a panel 2, or rather of dimensions which are less than the distance between the surfaces 2 e and 2 f of the panel 2 itself.

The different dimensions of the length L and the height H permit the panels 2 to be placed one over the other in order to form the above-mentioned continuous band of plastic, but leave between one plate 18 and two equally vertical plates 19 a space of dimensions which are sufficient to permit the direct adhesion of the plaster to the polystyrene of the panels 2.

According to the illustration which is shown in FIG. 3, the hinges 13, which permit the rotation of each portion 12 in relation to the relative crosspiece 11, consequently permit both the collapse of the formwork 1 in a transport configuration, in which the two panels 2 are arranged next to each other, and the positioning of the formwork 1 itself in a placement configuration (see FIG. 2) corresponding to the homologous placement configuration of the spacers 10, and in which the two panels 2 are arranged at a distance from each other which is equal to the length of the crosspiece 11.

According to what is better illustrated in FIGS. 10 and 11, the surface 16 s of each body 16 comprises a flat frontal face 161 which is arranged opposite the body 16 itself in relation to the relative element 11 a or 11 b, and two flat lateral faces 162, which are arranged parallel to each other and transverse to the face 161, and which are connected to the face 161 itself by means of two arch-shaped cams 163.

Each body 16 together with a relative pin 22 and together with the body 16 and the pin 22 which are arranged on the same axis B forms a hinge 13, and each body 16 is always arranged with its own surface 16 s abutting the relative plate 18, and the faces 161 and 162 define, respectively, the above-mentioned placement and transport configurations. In fact, in the transport configuration, a face 162 of each pair of faces 162 for each body 16 is arranged in contact with the relative plate 18, while, following the rotation of the hinge 13, the face 161 of each body 16 enters into contact with the relative plate 18 also blocking the panel 2. During the rotation, the cams 163 of each body 16 elastically deform the corresponding free end of the plates 18 exerting a determined amount of resistance against the rotation itself, and which is suitable for preventing both the accidental return of the panel 2 to its placement configuration once the rotation itself has been completed, as well as, obviously, the accidental displacement of the placement configuration.

In other words, the surface 16 s of each pin 22 defines a blocking element of the relative position between the crosspiece 11 and the portions 12, permitting both the safe transport of the panel 2, as well as a correct and rapid positioning of the panel 2 itself.

In addition, the surfaces 162 present in plan view a shape which is substantially that of a rectangular trapezoid, while the surface 161 presents in plan view the shape of an isosceles trapezoid, and is crossed by a groove 164, which is orientated parallel to the relative axis B, and is both suitable for permitting the relative body 16 a minimum of elastic deformability, as well as for avoiding the formation of external burrs during the moulding of the body 16 itself. The surfaces 161 and 162 are both arranged with their own major bases on the same side of the body 16 and confer s substantially conical development on each cam 163.

In the alternative form of embodiment of the formwork 1 which is illustrated in FIG. 7, the plates 19 are no longer completely outside the panel 2, but comprise a portion 19′ which is embedded inside the panel 2, and a portion 19″ which is exposed outside the panel 2 itself and which is integral with the embedded portion 19′. In this case, the plates 19 no longer have a completely flat geometry, but present a central concavity 30 defining the portion 19′, and two end fins 31, which define the portion 19″, and are arranged outside and abutting the panel 2.

In addition, the fins 31 are connected to a base 32 of the concavity 31 by respective connecting portions 33 which are oblique both in relation to the fins 31 and in relation to the base 32 themselves.

In the alternative form of embodiment of the formwork 1 which is instead illustrated in FIG. 8, the plates 19 present a configuration which is a mirror image of the configuration of the plate 19 which is shown in FIG. 7 and, thus, the fins 31 are embedded and define the portion 19′, while the base 32 of the concavity 30 is arranged outside and abutting the panel 2, and defines the portion 19″.

Finally, in the additional alternative form of embodiment of the formwork 1 which is illustrated in FIG. 9, the plates 19 present a Greek fret configuration, in which the portion 19′ and the portion 19″ are alternated in relation to each other, and are connected by portions 33 which are transverse to the portions 19′ and 19″.

The plates 19 in the three forms of embodiment of the formwork 1 which are illustrated in FIGS. 7, 8 and 9, thanks to the geometrical details which have been described above, may also present an overall development in plan view which is equal to the height H in that, in each case, the continuous bands of plastic which have been described will never, however, be formed.

A similar solution might prove to be advantageous in the case in which it may be necessary to superimpose a considerable number of panels 2 one on top of the other, in that the correspondence of a plate 19 of one panel with the plate 19 of the panel 2 beneath it and of the panel 2 above it permits the creation of vertical support rods with the contributing advantage of avoiding, as has been described above, the formation of the above-mentioned surface discontinuities.

It is intended that the present invention should not be limited to the forms of embodiment which are herein described and illustrated, which are to be considered as examples of forms of embodiment for the disposable formwork for insulated masonry in reinforced concrete which is the subject of the present invention, and which might be subject to further modifications relating to the shape and disposition of the parts, as well as to details pertaining to construction and assembly. 

1. Disposable formwork for insulated masonry in reinforced concrete, the formwork comprising two polystyrene panels which face each other and which are limited towards the outside by respective lateral surfaces, and at least two formwork spacers which are assembled together with the polystyrene panels, and presenting respective pairs of terminal end plates, wherein the terminal end plates extend to abut the relative lateral surfaces and partially occupy a height of the lateral surfaces.
 2. Disposable formwork according to claim 1, wherein said terminal end plates are made of plastic material and are arranged completely outside the relative polystyrene panels.
 3. Disposable form work according to claim 1, wherein said terminal end plates present a length which is of dimensions which are less than the height of a panel.
 4. Disposable formwork according to claim 1, wherein said terminal end plates are made of plastic material and are partially embedded inside the relative polystyrene panels.
 5. Disposable formwork according to claim 4, wherein said terminal end plates comprise a portion which is embedded inside the panel, and an exposed portion which is outside the panel and which is integral with the embedded portion.
 6. Disposable formwork according to claim 5, wherein said terminal end plates present, in plan view, an aggregate development of dimensions which are substantially equal to the height of a panel.
 7. Disposable formwork according to claim 5, wherein said terminal end plates comprise, for each embedded portion, a respective connecting portion for the relative exposed portion.
 8. Disposable formwork according to claim 7, wherein said connecting portion is arranged in an oblique position in relation to the relative embedded portion.
 9. Disposable formwork according to claim 7, wherein said connecting portion is arranged in a transverse position in relation to the relative embedded portion.
 10. Disposable formwork according to claim 1, further comprising two hinges which are associated with each formwork spacer in order to permit the collapse of the formwork in a transport configuration, and movement blocking devices for the hinges which are integrated into the hinges in order to block the two polystyrene panels in at least a placement position.
 11. Disposable formwork according to claim 10, wherein said blocking devices comprise, for each hinge, a grooved surface which is arranged in such a way as to abut a respective internal plate which is integral with the relative end plate.
 12. Disposable formwork according to claim 11, wherein said grooved surface comprises a first checking portion for said placement configuration, a second checking portion for said transport configuration, the two checking portions being suitable for being arranged in such a way as to abut said internal plate wherein the grooved surface further comprises, a transition portion which is interposed between the two checking portions thus defining a discontinuity between the two checking portions themselves in order to impede any accidental passage between said two configurations.
 13. Disposable formwork according to claim 12 wherein the two checking/curbing portions are defined by respective flat surfaces which are connected to each other by a substantially curved surface which defines, in turn, the said transition portion. 